I loved Fallout 3 more than any game ever when it came out, and it's still an amazing game, but I feel like people irrationally hate on New Vegas. It's just an all-around better game. Everything just works better, from companions to shooting mechanics, and the story having so many different ways to be played out. Also there is a huge city with casinos where you can gamble.

I prefer Fallout 3 but because it's the exploration I love about these kind of games and the Fallout 3 environment had more landmarks, more obscure unimportant locations that still had its own small interesting story to discover.
F:NV did, however, crush Fallout 3 in the line of a coherent story. If you took the time to analyze Fallout 3, it reveals a lot of plot holes.

I think most people hated how New Vegas was poorly made. For me,I had built my computer specifically to handle New Vegas with the best texture pack mods and I built it to handle anything New Vegas could throw at it.

Guess what? I bought mine on launch,and it ran like ****. I couldn't even get it to run correctly,micro stuttering jaggy lines,and long range texture flickering. Even after mods such as the New Vegas Error Corrections and the micro stutter removers,it still would run like crap.

After 120+ mods I finally got it to run stable-ish. I liked the game,but I hated the Mojaves enviroment. Wandering about in the desert was alright,but it got boring when I fought more deathclaws than people.